What's the point of this kind of macros?

Question

#define NAME(x) TEXT(x)
#define TEXT(quote) __TEXT(quote)   // r_winnt
#define __TEXT(quote) quote         // r_winnt

The above is from winNT.h, isn't NAME("Virtual Cam") the same as "Virtual Cam",what's the point to use this macro?

Answer 1

__TEXT macro expansion is selected based on whether UNICODE flag is defined or not. If not it just expands to quote else it will append L to the quote so that it becomes L"Virtual Cam" . This string is interpreted as a wide char string.

Answer 2

Depends on if your system is #defined to use Unicode. Then it will automatically change the literal for you to be a wide literal instead of a char literal.